Jonny Wilkinson has dramatically turned down an invitation to join this summer's British and Irish Lions tour, sparing Australia a reunion with their old nemesis. Warren Gatland, the Lions head coach, rang the World Cup-winning fly-half on Monday to offer him the chance of joining the squad, but Wilkinson told him he will not be available to fly out on 27 May because of his commitments with Toulon and because he is also uncertain about his state of fitness.

There remains the faint possibility of Wilkinson being invited to join the tour as an injury replacement but Gatland revealed the former England outside-half was considering having an operation which would rule him out of contention.

"I asked Jonny if he could tour and he said he wasn't available. I wouldn't have made the phone call if it wasn't to offer him a place on the tour," said Gatland, after unveiling a 37-man squad. "He appreciated the call but he said he was struggling with his body and was managing himself week to week.

"I think physically he would struggle to do a tour. He was honest about himself and said: 'I'm hanging on with my fingernails here at the moment and I probably need another operation.' I also told him that we wanted everyone on the tour to be on the plane to Hong Kong and he couldn't make that commitment because he's committed to Toulon."

With only two specialist fly-halves named, however, the temptation to wheel out the 33-year-old Wilkinson for one last international hurrah may yet resurface should injuries strike. England's record point scorer was outstanding at the weekend as he helped steer Toulon into the Heineken Cup final at the expense of Saracens and Owen Farrell. The latter has been named in the Lions tour party despite a distinctly shaky display in that match at Twickenham.

"It was a hugely proud moment for me to be called by Warren Gatland, to be told that they were thinking of me in this way," Wilkinson admitted last night. "I was phenomenally proud to be considered for the Lions, so it's very disappointing that I'm unavailable.

"If Toulon manage to get through to the final of the Top 14, my absolute priority lies with them.

"I told him where I am at the moment, that there's a bit of day-to-day management where my body is concerned," Wilkinson told The Times. "I'll see how I am at the end of the club season and if Warren needs me and I am able to get involved, that would be fabulous."

Had Toulon not been a strong bet to reach the French championship final on 1 June, Wilkinson's stance might have been different. He has signed a year's contract extension but potentially participating in two matches a week on such an intense tour would have been too much. He showed few signs, nevertheless, of slowing up against Saracens and may yet be available to answer an SOS call from Australia.

"We asked him about what happens if there is an injury later in the tour and he said: 'We can have that conversation later if that crops up,'" said Gatland. "We left it open-ended. You never know if you pick up a few injuries what's going to happen later in the tour."

By sounding out Wilkinson in the certain knowledge he would be committed to Toulon until the beginning of June, Gatland has neatly deflected any possible public criticism that the Lions have ignored a potential series-clinching candidate. It may be a decade since Wilkinson's drop-goal in Sydney clinched the World Cup for England, but his presence in a Lions jersey would still have sent a collective shiver down antipodean spines.

Instead, for now at least, Australia will have to concern themselves with other "lumps of red meat" as one paper has already phrased it.

The Lions tour manager, Andy Irvine, has warned his players to be wary when using social media sites such as Twitter or Facebook. "On social media these days you can make a mistake and it can be around the world," Irvine said. "It takes years to build up a good reputation but you can lose it in seconds. We are alert to that. You have to have a good set of tourists, a good set of guys, and I am very confident there is not one [player] on the tour who comes even close to being a concern. We want the players to enjoy themselves, because that is part and parcel of touring, but within reason."